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  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
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<body>
  <script>
    //8. 获取<p class='demo'>hello JavaScript</p>内部文案
    let reg = /^<.+>(.+)<.+>$/;
    let str = "<p class='demo'>hello JavaScript</p>"
    console.log(str.match(reg)[1]);
  </script>
</body>
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